Issue 0156: Should calls to fsetpos with positions in closed and reopened streams be undefined?

This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.

Authors: Clive D.W. Feather, BSI
Date: 1995-10-16
Submitted against: C90
Status: Fixed
Fixed in: C99
Converted from: dr.htm, dr_156.html

Submitted to BSI by Clive D.W. Feather clive@sco.com.

In this Defect Report, identifiers lexically identical to those declared in standard headers refer to the identifiers declared in those standard headers, whether or not the header is explicitly mentioned. This Defect Report has been prepared with considerable help from Mark Brader, Jutta Degener, Ronald Guilmette, and a person whose employment conditions require anonymity. However, except where stated, opinions expressed or implied should not be assumed to be those of any person other than myself.

Defect Report UK 004: Closed streams

Calls to fsetpos with positions in closed and reopened streams are permitted, but should be undefined.

The definition of fsetpos (subclause 7.9.9.3) requires the fpos_t argument to have a value generated by a successful call to fgetpos on the same stream. However, it does not require the stream to refer to the same file. If the stream does not so refer, the effect should be explicitly undefined.

Suggested Technical Corrigendum:

In subclause 7.9.9.3, change:

... an earlier call to the fgetpos function on the same stream.

to:

... an earlier call to the fgetpos function on the same stream; there shall not have been an intervening call to the fclose or freopen function with that stream.

Comment from WG14 on 1997-09-23:

Technical Corrigendum

In subclause 7.9.9.2, page 145, change:

... an earlier successful call to the ftell function on the same stream ...

to:

... an earlier successful call to the ftell function on a stream associated with the same file ...

In subclause 7.9.9.3, page 146, change:

... an earlier successful call to the fgetpos function on the same stream.

to:

... an earlier successful call to the fgetpos function on a stream associated with the same file.